Catalyst enhanced seamless ruthenium gap fill

ABSTRACT

Methods of depositing a metal film with high purity are discussed. A catalyst enhanced CVD process is utilized comprising an alkyl halide catalyst soak and a precursor exposure. The precursor comprises a metal precursor having the general formula (I): M-L1(L2)y, wherein M is a metal, L1 is an aromatic ligand, L2 is an aliphatic ligand, and y is a number in the range of from 2 to 8 to form a metal film on the substrate surface, wherein the L2 comprises 1,5-hexdiene, 1,4-hexadiene, and less than 5% of 1,3-hexadiene. Selective deposition of a metal film with high purity on a metal surface over a dielectric surface is described.

CROSS-REFERENCE TO RELATED APPLICATIONS

This application claims priority to U.S. Provisional Application No.62/959,509, filed Jan. 10, 2020 and to U.S. Provisional Application No.62/993,943, filed Mar. 24, 2020, the entire disclosures of which arehereby incorporated by reference herein.

TECHNICAL FIELD

Embodiments of the disclosure generally relate to methods for depositingmetal films. One or more embodiments of the disclosure are directed tomethods for depositing metal films. One or more embodiments of thedisclosure relate to the selective deposition of metal films.

BACKGROUND

The semiconductor industry continues to strive for continuous deviceminiaturization that is driven by the need for mobile andhigh-performance systems in emerging industries such as autonomousvehicles, virtual reality, and future mobile devices. To accomplish thisfeat, new, high-performance materials are needed to circumvent inherentengineering and physics issues encountered in rapid reduction offeatures in microelectronic devices.

Ruthenium is a proposed material for integration owing to its highmelting point (ability to withstand high current densities), exceptionaldensity, and ability to conduct electrical current. Ruthenium andruthenium containing thin films have attractive material and conductiveproperties. Ruthenium films have been proposed for applications fromfront end to back end parts of semiconductor and microelectronicdevices.

Thin-films of ruthenium would ideally be deposited using thin-filmdeposition techniques such as Chemical Vapor Deposition (CVD) and AtomicLayer Deposition (ALD) owing to their ability to deposit material in ahigh-throughput and precise fashion.

Deposited ruthenium films often differ from bulk ruthenium materials.There is particular challenges in depositing ruthenium films with highpurity (>99% Ru), especially as gap fill materials. Previous solutions,including the use of oxygen reactants, produced films with greaterroughness than bulk materials. Similarly, hydrogen reactants providedgreater impurities which then required a subsequent annealing step.Finally, plasma deposition processes were unable to deposit gap fillmaterials without creating a seam and potentially damaging theunderlying substrate.

Therefore there is a need for methods and materials for depositing highpurity conformal ruthenium films as gap fill.

Therefore there is a need for methods and materials for depositing highpurity conformal ruthenium films as gap fill. There is also a need formethods and materials for depositing ruthenium films as gap fill withoutseams or voids.

Additionally, as the design of semiconductor devices evolve, precisionmaterial manufacturing in the semiconductor industry has entered an eraof atomic scale dimensions. At the atomic scale, with only tens of atomsat stake, there is little margin for error. This unprecedented challengedemands new material processing techniques which have atomic levelprecision. However, increasing the complexity of the process flowrequired in atomic scale device manufacturing can significantly lowerthroughput and increase the cost of manufacturing.

Selective deposition technologies offer the potential forchemically-selective atomic-layer precision in semiconductor filmpatterning. Selective deposition also offers the potential for simplerprocess flows by eliminating lithography or other processes.

Selective deposition of materials can be accomplished in a variety ofways. For instance, some processes may have inherent selectivity tosurfaces based on their surface chemistry. These processes are fairlyrare and usually need to have surfaces with drastically differentsurface energies, such as metals and dielectrics.

Therefore there is a need for methods of selectively depositing metalfilms on metallic surfaces over dielectric surfaces, or vice versa.

SUMMARY

One or more embodiments of the disclosure are directed to a method offorming a film. The method comprises forming a film on a substratesurface by exposing the substrate surface to a precursor of generalformula (I): M-L₁(L₂)_(y), wherein M is a metal, L₁ is an aromaticligand, L₂ is an aliphatic ligand, and y is a number in the range offrom 2 to 8, wherein L₂ comprises 1,5-hexdiene, 1,4-hexadiene, and lessthan 5% of 1,3-hexadiene.

Additional embodiments of the disclosure are directed to a method offorming a film. In one or more embodiments, a method comprises exposinga substrate surface to a halogen catalyst to form an activated substratesurface; and exposing the activated substrate surface to a precursor ofgeneral formula (I): M-L₁(L₂)_(y), wherein M is a metal, L₁ is anaromatic ligand, L₂ is an aliphatic ligand, and y is a number in therange of from 2 to 8 to form a metal film on the substrate surface,wherein the L₂ comprises 1,5-hexdiene, 1,4-hexadiene, and less than 5%of 1,3-hexadiene.

Further embodiments are directed to a non-transitory computer readablemedium including instructions, that, when executed by a controller of aprocessing chamber, causes the processing chamber to perform operationsof: exposing a substrate surface to a halogen catalyst to form anactivated substrate surface; and flowing a precursor into a processingvolume of the processing chamber having the substrate, the precursorhaving general formula (I): M-L₁(L₂)_(y), wherein M is a metal, L₁ is anaromatic ligand, L₂ is an aliphatic ligand, and y is a number in therange of from 2 to 8, wherein the L₂ comprises 1,5-hexdiene,1,4-hexadiene, and less than 5% of 1,3-hexadiene.

BRIEF DESCRIPTION OF THE DRAWINGS

So that the manner in which the above recited features of the presentdisclosure can be understood in detail, a more particular description ofthe disclosure, briefly summarized above, may be had by reference toembodiments, some of which are illustrated in the appended drawings. Itis to be noted, however, that the appended drawings illustrate onlytypical embodiments of this disclosure and are therefore not to beconsidered limiting of its scope, for the disclosure may admit to otherequally effective embodiments.

FIG. 1 illustrates a schematic view of a processing platform inaccordance with one or more embodiments of the disclosure;

FIG. 2 illustrates a cross-sectional view of a batch processing chamberin accordance with one or more embodiments of the disclosure;

FIG. 3 illustrates a partial perspective view of a batch processingchamber in accordance with one or more embodiments of the disclosure;

FIG. 4 illustrates a schematic view of a batch processing chamber inaccordance with one or more embodiments of the disclosure;

FIG. 5 illustrates a schematic view of a portion of a wedge shaped gasdistribution assembly for use in a batch processing chamber inaccordance with one or more embodiments of the disclosure;

FIG. 6 illustrates a schematic view of a batch processing chamber inaccordance with one or more embodiments of the disclosure;

FIG. 7 illustrates a process flow diagram of a process sequence for theformation of a metal layer using a two pulse cyclical depositiontechnique according to one or more embodiments of the disclosure;

FIG. 8 illustrates a process flow diagram of a process sequence for theformation of a ruthenium layer according to one or more embodiments ofthe disclosure;

FIG. 9 illustrates a cross-sectional view of an exemplary substrate inaccordance with one or more embodiments of the disclosure; and

FIGS. 10A-10D illustrate an exemplary substrate during processingaccording to one or more embodiments of the disclosure.

DETAILED DESCRIPTION

Before describing several exemplary embodiments of the disclosure, it isto be understood that the disclosure is not limited to the details ofconstruction or process routines set forth in the following description.The disclosure is capable of other embodiments and of being practiced orbeing carried out in various ways.

As used herein, the term “substrate”, “substrate surface”, or the like,refers to any substrate or material surface formed on a substrate uponwhich processing is performed. For example, a substrate surface on whichprocessing can be performed include, but are not limited to, materialssuch as silicon, silicon oxide, strained silicon, silicon on insulator(SOI), carbon doped silicon oxides, silicon nitride, doped silicon,germanium, gallium arsenide, glass, sapphire, and any other materialssuch as metals, metal nitrides, metal alloys, and other conductivematerials, depending on the application. Substrates include, withoutlimitation, semiconductor wafers. Substrates may be exposed to apretreatment process to polish, etch, reduce, oxidize, hydroxylate (orotherwise generate or graft target chemical moieties to impart chemicalfunctionality), anneal and/or bake the substrate surface. In addition toprocessing directly on the surface of the substrate itself, in thepresent disclosure, any of the film processing steps disclosed may alsobe performed on an underlayer formed on the substrate as disclosed inmore detail below, and the term “substrate surface” is intended toinclude such underlayer as the context indicates. Thus for example,where a film/layer or partial film/layer has been deposited onto asubstrate surface, the exposed surface of the newly deposited film/layerbecomes the substrate surface. What a given substrate surface compriseswill depend on what materials are to be deposited, as well as theparticular chemistry used.

“Atomic layer deposition” or “cyclical deposition” as used herein refersto the sequential exposure of two or more reactive compounds to deposita layer of material on a substrate surface. As used in thisspecification and the appended claims, the terms “reactive compound”,“reactive gas”, “reactive species”, “precursor”, “process gas” and thelike are used interchangeably to mean a substance with a species capableof reacting with the substrate surface or material on the substratesurface in a surface reaction (e.g., chemisorption, oxidation,reduction). The substrate, or portion of the substrate, is exposedseparately to the two or more reactive compounds which are introducedinto a reaction zone of a processing chamber. In a time-domain ALDprocess, exposure to each reactive compound is separated by a time delayto allow each compound to adhere and/or react on the substrate surfaceand then be purged from the processing chamber. These reactive compoundsare said to be exposed to the substrate sequentially. In a spatial ALDprocess, different portions of the substrate surface, or material on thesubstrate surface, are exposed simultaneously to the two or morereactive compounds so that any given point on the substrate issubstantially not exposed to more than one reactive compoundsimultaneously. As used in this specification and the appended claims,the term “substantially” used in this respect means, as will beunderstood by those skilled in the art, that there is the possibilitythat a small portion of the substrate may be exposed to multiplereactive gases simultaneously due to diffusion, and that thesimultaneous exposure is unintended.

In one aspect of a time-domain ALD process, a first reactive gas (i.e.,a first precursor or compound A) is pulsed into the reaction zonefollowed by a first time delay. Next, a second precursor or compound Bis pulsed into the reaction zone followed by a second delay. During eachtime delay, a purge gas, such as argon, is introduced into theprocessing chamber to purge the reaction zone or otherwise remove anyresidual reactive compound or reaction by-products from the reactionzone. Alternatively, the purge gas may flow continuously throughout thedeposition process so that only the purge gas flows during the timedelay between pulses of reactive compounds. The reactive compounds arealternatively pulsed until a desired film or film thickness is formed onthe substrate surface. In either scenario, the ALD process of pulsingcompound A, purge gas, compound B and purge gas is a cycle. A cycle canstart with either compound A or compound B and continue the respectiveorder of the cycle until achieving a film with the predeterminedthickness.

In an embodiment of a spatial ALD process, a first reactive gas andsecond reactive gas (e.g., metal precursor gas) are deliveredsimultaneously to the reaction zone but are separated by an inert gascurtain and/or a vacuum curtain. The substrate is moved relative to thegas delivery apparatus so that any given point on the substrate isexposed to the first reactive gas and the second reactive gas.

As used herein, “chemical vapor deposition” refers to a process in whicha substrate surface is exposed to precursors and/or co-reagentssimultaneous or substantially simultaneously. As used herein,“substantially simultaneously” refers to either co-flow or where thereis overlap for a majority of exposures of the precursors.

As used in this specification and the appended claims, the terms“reactive compound”, “reactive gas”, “reactive species”, “precursor”,“process gas” and the like are used interchangeably to mean a substancewith a species capable of reacting with the substrate surface ormaterial on the substrate surface in a surface reaction (e.g.,chemisorption, oxidation, reduction).

One or more embodiments of the disclosure are directed to processes thatuse a reaction chamber with multiple gas ports that can be used forintroduction of different chemicals or plasma gases. Spatially, thesegas ports (also referred to as channels) are separated by inert purginggases and/or vacuum pumping holes to create a gas curtain that minimizesor eliminates mixing of gases from different gas ports to avoid unwantedgas phase reactions. Wafers moving through these different spatiallyseparated ports get sequential and multiple surface exposures todifferent chemical or plasma environment so that layer by layer filmgrowth in spatial ALD mode or surface etching process occur. In one ormore embodiments, the processing chamber has modular architectures ongas distribution components and each modular component has independentparameter control (e.g., RF or gas flow) to provide flexibility tocontrol, for example, gas flow and/or RF exposure.

One or more embodiments of the disclosure provide methods for depositinga high purity metal film. The methods of various embodiments use atomiclayer deposition (ALD) or chemical vapor deposition (CVD) to providepure or nearly pure metal films. While exemplary embodiments of thisdisclosure refer to the deposition of ruthenium, it is conceived thatthe principles of this disclosure enable the deposition of highly puremetal films regardless of metal.

One or more embodiments of the disclosure provide methods of selectivelydepositing metal films on a metal surface over a dielectric surface. Oneor more embodiments of the disclosure provide methods of selectivelydepositing metal films on a dielectric surface over a metal surface. Asused in this specification and the appended claims, the term“selectively depositing a film on one surface over another surface”, andthe like, means that a first amount of the film is deposited on thefirst surface and a second amount of film is deposited on the secondsurface, where the second amount of film is less than the first amountof film, or no film is deposited on the second surface.

The term “over” used in this regard does not imply a physicalorientation of one surface on top of another surface, rather arelationship of the thermodynamic or kinetic properties of the chemicalreaction with one surface relative to the other surface. For example,selectively depositing a ruthenium film onto a metal surface over adielectric surface means that the ruthenium film deposits on the metalsurface and less or no ruthenium film deposits on the dielectricsurface; or that the formation of a ruthenium film on the metal surfaceis thermodynamically or kinetically favorable relative to the formationof a ruthenium film on the dielectric surface.

The selectivity of a deposition process is generally expressed as amultiple of growth rate. For example, if one surface is grown (ordeposited on) 25 times faster than a different surface, the processwould be described as having a selectivity of 25:1. In this regard,higher ratios indicate more selective processes.

One or more embodiments of the disclosure advantageously provide methodsfor depositing metal films with high purity. Accordingly, these highlypure films exhibit similar properties to their associated bulk metallicmaterials. For example, one or more embodiments of this disclosureprovide ruthenium films which are smoother and have lower resistancethan ruthenium films deposited by conventional oxygen or hydrogenreactant processes. One or more embodiments of this disclosureadvantageously provide metal films which conformally fill gaps without aseam.

One or more embodiments of the disclosure advantageously provide for theselective deposition of metal films with high purity on metallicsurfaces over dielectric surfaces. For example, selectively depositingruthenium on copper over dielectrics advantageously provides coppercapping layers without additional etch or lithography steps.Additionally, selective deposition may also enable bottom-up gap fillfor trenches with metal contacts at the bottom and dielectric sidewalls.

One or more embodiments of the disclosure advantageously provide for theselective deposition of metal films with high purity on dielectricsurfaces over metallic surfaces. For example, selectively depositingmetals over dielectrics advantageously provides metal layers on barriersor other dielectrics in back end applications.

One or more embodiments of the disclosure utilize a spatial ALD processwhich is performed on a processing platform as disclosed herein.Referring to the Figures, FIG. 1 shows a processing platform 100 inaccordance with one or more embodiments of the disclosure. Theembodiment shown in FIG. 1 is merely representative of one possibleconfiguration and should not be taken as limiting the scope of thedisclosure. For example, in one or more embodiments, the processingplatform 100 has different numbers of process chambers, buffer chambers,and robot configurations.

The processing platform 100 includes a central transfer station 110which has a plurality of sides 111, 112, 113, 114, 115, 116. The centraltransfer station 110 shown has a first side 111, a second side 112, athird side 113, a fourth side 114, a fifth side 115 and a sixth side116. Although six sides are shown, those skilled in the art willunderstand that there can be any suitable number of sides to the centraltransfer station 110 depending on, for example, the overallconfiguration of the processing platform 100.

The transfer station 110 has a robot 117 positioned therein. The robot117 can be any suitable robot capable of moving a wafer duringprocessing. In one or more embodiments, the robot 117 has a first arm118 and a second arm 119. The first arm 118 and second arm 119 can bemoved independently of the other arm. The first arm 118 and second arm119 can move in the x-y plane and/or along the z-axis. In one or moreembodiments, the robot 117 includes a third arm or a fourth arm (notshown). Each of the arms can move independently of other arms.

A first batch processing chamber 120 can be connected to a first side111 of the central transfer station 110. The first batch processingchamber 120 can be configured to process x wafers at a time for a batchtime. In one or more embodiments, the first batch processing chamber 120can be configured to process in the range of about four (x=4) to about12 (x=12) wafers at the same time. In one or more embodiments, the firstbatch processing chamber 120 is configured to process six (x=6) wafersat the same time. As will be understood by the skilled artisan, whilethe first batch processing chamber 120 can process multiple wafersbetween loading/unloading of an individual wafer, each wafer may besubjected to different process conditions at any given time. Forexample, a spatial atomic layer deposition chamber, like that shown inFIGS. 2 through 6, expose the wafers to different process conditions indifferent processing regions so that as a wafer is moved through each ofthe regions, the process is completed.

FIG. 2 shows a cross-section of a processing chamber 200 including a gasdistribution assembly 220, also referred to as injectors or an injectorassembly, and a susceptor assembly 240. The gas distribution assembly220 is any type of gas delivery device used in a processing chamber. Thegas distribution assembly 220 includes a front surface 221 which facesthe susceptor assembly 240. The front surface 221 can have any number orvariety of openings to deliver a flow of gases toward the susceptorassembly 240. The gas distribution assembly 220 also includes an outerperipheral edge 224 which in the embodiments shown, is substantiallyround.

The specific type of gas distribution assembly 220 used can varydepending on the particular process being used. Embodiments of thedisclosure can be used with any type of processing system where the gapbetween the susceptor and the gas distribution assembly is controlled.While various types of gas distribution assemblies can be employed(e.g., showerheads), embodiments of the disclosure may be particularlyuseful with spatial gas distribution assemblies which have a pluralityof substantially parallel gas channels. As used in this specificationand the appended claims, the term “substantially parallel” means thatthe elongate axis of the gas channels extend in the same generaldirection. There can be slight imperfections in the parallelism of thegas channels. In a binary reaction, the plurality of substantiallyparallel gas channels can include at least one first reactive gas Achannel, at least one second reactive gas B channel, at least one purgegas P channel and/or at least one vacuum V channel. The gases flowingfrom the first reactive gas A channel(s), the second reactive gas Bchannel(s) and the purge gas P channel(s) are directed toward the topsurface of the wafer. Some of the gas flow moves horizontally across thesurface of the wafer and out of the process region through the purge gasP channel(s). A substrate moving from one end of the gas distributionassembly to the other end will be exposed to each of the process gasesin turn, forming a layer on the substrate surface.

In one or more embodiments, the gas distribution assembly 220 is a rigidstationary body made of a single injector unit. In one or moreembodiments, the gas distribution assembly 220 is made up of a pluralityof individual sectors (e.g., injector units 222), as shown in FIG. 3.Either a single piece body or a multi-sector body can be used with thevarious embodiments of the disclosure described.

In one or more embodiments, a susceptor assembly 240 is positionedbeneath the gas distribution assembly 220. The susceptor assembly 240includes a top surface 241 and at least one recess 242 in the topsurface 241. The susceptor assembly 240 also has a bottom surface 243and an edge 244. The at least one recess 242 can be any suitable shapeand size depending on the shape and size of the substrates 60 beingprocessed. In the embodiments shown in FIG. 2, the recess 242 has a flatbottom to support the bottom of the wafer; however, the bottom of therecess can vary. In one or more embodiments, the recess has step regionsaround the outer peripheral edge of the recess which are sized tosupport the outer peripheral edge of the wafer. The amount of the outerperipheral edge of the wafer that is supported by the steps can varydepending on, for example, the thickness of the wafer and the presenceof features already present on the back side of the wafer.

In one or more embodiments, as shown in FIG. 2, the recess 242 in thetop surface 241 of the susceptor assembly 240 is sized so that asubstrate 60 supported in the recess 242 has a top surface 61substantially coplanar with the top surface 241 of the susceptor 240. Asused in this specification and the appended claims, the term“substantially coplanar” means that the top surface of the wafer and thetop surface of the susceptor assembly are coplanar within ±0.2 mm. Inone or more embodiments, the top surfaces are coplanar within 0.5 mm,±0.4 mm, ±0.35 mm, ±0.30 mm, ±0.25 mm, ±0.20 mm, ±0.15 mm, ±0.10 mm or±0.05 mm.

The susceptor assembly 240 of FIG. 2 includes a support post 260 whichis capable of lifting, lowering and rotating the susceptor assembly 240.The susceptor assembly may include a heater, or gas lines, or electricalcomponents within the center of the support post 260. The support post260 may be the primary means of increasing or decreasing the gap betweenthe susceptor assembly 240 and the gas distribution assembly 220, movingthe susceptor assembly 240 into proper position. The susceptor assembly240 may also include fine tuning actuators 262 which can makemicro-adjustments to susceptor assembly 240 to create a predeterminedgap 270 between the susceptor assembly 240 and the gas distributionassembly 220.

In one or more embodiments, the gap 270 distance is in the range ofabout 0.1 mm to about 5.0 mm, or in the range of about 0.1 mm to about3.0 mm, or in the range of about 0.1 mm to about 2.0 mm, or in the rangeof about 0.2 mm to about 1.8 mm, or in the range of about 0.3 mm toabout 1.7 mm, or in the range of about 0.4 mm to about 1.6 mm, or in therange of about 0.5 mm to about 1.5 mm, or in the range of about 0.6 mmto about 1.4 mm, or in the range of about 0.7 mm to about 1.3 mm, or inthe range of about 0.8 mm to about 1.2 mm, or in the range of about 0.9mm to about 1.1 mm, or about 1 mm.

The processing chamber 200 shown in the Figures is a carousel-typechamber in which the susceptor assembly 240 can hold a plurality ofsubstrates 60. As shown in FIG. 3, the gas distribution assembly 220 mayinclude a plurality of separate injector units 222, each injector unit222 being capable of depositing a film on the wafer, as the wafer ismoved beneath the injector unit. Two pie-shaped injector units 222 areshown positioned on approximately opposite sides of and above thesusceptor assembly 240. This number of injector units 222 is shown forillustrative purposes only. It will be understood that more or lessinjector units 222 can be included. In one or more embodiments, thereare a sufficient number of pie-shaped injector units 222 to form a shapeconforming to the shape of the susceptor assembly 240. In one or moreembodiments, each of the individual pie-shaped injector units 222 may beindependently moved, removed and/or replaced without affecting any ofthe other injector units 222. For example, one segment may be raised topermit a robot to access the region between the susceptor assembly 240and gas distribution assembly 220 to load/unload substrates 60.

In one or more embodiments, processing chambers having multiple gasinjectors can be used to process multiple wafers simultaneously so thatthe wafers experience the same process flow. For example, as shown inFIG. 4, the processing chamber 200 has four gas injector assemblies andfour substrates 60. At the outset of processing, the substrates 60 canbe positioned between the gas distribution assemblies 220. Rotating 17the susceptor assembly 240 by 45° will result in each substrate 60 whichis between gas distribution assemblies 220 to be moved to a gasdistribution assembly 220 for film deposition, as illustrated by thedotted circle under the gas distribution assemblies 220. An additional45° rotation would move the substrates 60 away from the gas distributionassemblies 220. The number of substrates 60 and gas distributionassemblies 220 can be the same or different. In One or more embodiments,there are the same numbers of wafers being processed as there are gasdistribution assemblies. In one or more embodiments, the number ofwafers being processed are fraction of or an integer multiple of thenumber of gas distribution assemblies. For example, if there are fourgas distribution assemblies, there are 4× wafers being processed, wherex is an integer value greater than or equal to one. In an exemplaryembodiment, the gas distribution assembly 220 includes eight processregions separated by gas curtains and the susceptor assembly 240 canhold six wafers.

The processing chamber 200 shown in FIG. 4 is merely representative ofone possible configuration and should not be taken as limiting the scopeof the disclosure. Here, the processing chamber 200 includes a pluralityof gas distribution assemblies 220. In the embodiments shown, there arefour gas distribution assemblies 220 (also called injector assemblies)evenly spaced about the processing chamber 200. The processing chamber200 shown is octagonal; however, those skilled in the art willunderstand that this is one possible shape and should not be taken aslimiting the scope of the disclosure. The gas distribution assemblies220 shown are trapezoidal, but can be a single circular component ormade up of a plurality of pie-shaped segments, like that shown in FIG.3.

The embodiment shown in FIG. 4 includes a load lock chamber 280, or anauxiliary chamber like a buffer station. This chamber 280 is connectedto a side of the processing chamber 200 to allow, for example thesubstrates (also referred to as substrates 60) to be loaded/unloadedfrom the processing chamber 200. A wafer robot may be positioned in thechamber 280 to move the substrate onto the susceptor.

Rotation of the carousel (e.g., the susceptor assembly 240) can becontinuous or intermittent (discontinuous). In continuous processing,the wafers are constantly rotating so that they are exposed to each ofthe injectors in turn. In discontinuous processing, the wafers can bemoved to the injector region and stopped, and then to the region 84between the injectors and stopped. For example, the carousel can rotateso that the wafers move from an inter-injector region across theinjector (or stop adjacent the injector) and on to the nextinter-injector region where the carousel can pause again. Pausingbetween the injectors may provide time for additional processingroutines between each layer deposition (e.g., exposure to plasma).

FIG. 5 shows a sector or portion of a gas distribution assembly 220,which may be referred to as an injector unit. The injector units 222 canbe used individually or in combination with other injector units. Forexample, as shown in FIG. 6, four of the injector units 222 of FIG. 5are combined to form a single gas distribution assembly 220. (The linesseparating the four injector units are not shown for clarity.) While theinjector unit 222 of FIG. 5 has both a first reactive gas port 225 and asecond gas port 235 in addition to purge gas ports 255 and vacuum ports245, an injector unit 222 does not need all of these components.

Referring to both FIGS. 5 and 6, a gas distribution assembly 220 inaccordance with one or more embodiments may comprise a plurality ofsectors (or injector units 222) with each sector being identical ordifferent. The gas distribution assembly 220 is positioned within theprocessing chamber and comprises a plurality of elongate gas ports 225,235, 245 in a front surface 221 of the gas distribution assembly 220.The plurality of elongate gas ports 225, 235, 245, 255 extend from anarea adjacent the inner peripheral edge 223 toward an area adjacent theouter peripheral edge 224 of the gas distribution assembly 220. Theplurality of gas ports shown include a first reactive gas port 225, asecond gas port 235, a vacuum port 245 which surrounds each of the firstreactive gas ports and the second reactive gas ports and a purge gasport 255.

With reference to the embodiments shown in FIG. 5 or 6, when statingthat the ports extend from at least about an inner peripheral region toat least about an outer peripheral region, however, the ports can extendmore than just radially from inner to outer regions. The ports canextend tangentially as vacuum port 245 surrounds reactive gas port 225and reactive gas port 235. In the embodiments shown in FIGS. 5 and 6,the wedge shaped reactive gas ports 225, 235 are surrounded on alledges, including adjacent the inner peripheral region and outerperipheral region, by a vacuum port 245.

Referring to FIG. 5, as a substrate moves along path 227, each portionof the substrate surface is exposed to the various reactive gases. Tofollow the path 227, the substrate will be exposed to, or “see”, a purgegas port 255, a vacuum port 245, a first reactive gas port 225, a vacuumport 245, a purge gas port 255, a vacuum port 245, a second gas port 235and a vacuum port 245. Thus, at the end of the path 227 shown in FIG. 5,the substrate has been exposed to the first reactive gas and the secondreactive gas to form a layer. The injector unit 222 shown makes aquarter circle but could be larger or smaller. The gas distributionassembly 220 shown in FIG. 6 can be considered a combination of four ofthe injector units 222 of FIG. 3 connected in series.

The injector unit 222 of FIG. 5 shows a gas curtain 250 that separatesthe reactive gases. The term “gas curtain” is used to describe anycombination of gas flows or vacuum that separate reactive gases frommixing. The gas curtain 250 shown in FIG. 5 comprises the portion of thevacuum port 245 next to the first reactive gas port 225, the purge gasport 255 in the middle and a portion of the vacuum port 245 next to thesecond gas port 235. This combination of gas flow and vacuum can be usedto prevent or minimize gas phase reactions of the first reactive gas andthe second reactive gas.

Referring to FIG. 6, the combination of gas flows and vacuum from thegas distribution assembly 220 form a separation into a plurality ofprocess regions 350. The process regions are roughly defined around theindividual gas ports 225, 235 with the gas curtain 250 between 350. Theembodiments shown in FIG. 6 makes up eight separate process regions 350with eight separate gas curtains 250 between. A processing chamber canhave at least two process regions. In One or more embodiments, there areat least three, four, five, six, seven, eight, nine, 10, 11 or 12process regions.

During processing a substrate may be exposed to more than one processregion 350 at any given time. However, the portions that are exposed tothe different process regions will have a gas curtain separating thetwo. For example, if the leading edge of a substrate enters a processregion including the second gas port 235, a middle portion of thesubstrate will be under a gas curtain 250 and the trailing edge of thesubstrate will be in a process region including the first reactive gasport 225.

A factory interface (as shown in FIG. 4), which can be, for example, aload lock chamber 280, is shown connected to the processing chamber 200.A substrate 60 is shown superimposed over the gas distribution assembly220 to provide a frame of reference. The substrate 60 may often sit on asusceptor assembly to be held near the front surface 221 of the gasdistribution assembly 220. The substrate 60 is loaded via the factoryinterface into the processing chamber 200 onto a substrate support orsusceptor assembly (see FIG. 4). The substrate 60 can be shownpositioned within a process region because the substrate is locatedadjacent the first reactive gas port 225 and between two gas curtains250 a, 250 b. Rotating the substrate 60 along path 227 will move thesubstrate counter-clockwise around the processing chamber 200. Thus, thesubstrate 60 will be exposed to the first process region 350 a throughthe eighth process region 350 h, including all process regions between.

One or more embodiments of the disclosure are directed to a processingchamber 200 with a plurality of process regions 350 a-350 h with eachprocess region separated from an adjacent region by a gas curtain 250.For example, the processing chamber shown in FIG. 6. The number of gascurtains and process regions within the processing chamber can be anysuitable number depending on the arrangement of gas flows. Theembodiment shown in FIG. 6 has eight gas curtains 250 and eight processregions 350 a-350 h.

Referring back to FIG. 1, the processing platform 100 includes atreatment chamber 140 connected to a second side 112 of the centraltransfer station 110. The treatment chamber 140 of one or moreembodiments is configured to expose the wafers to a process to treat thewafers before and/or after processing in first batch processing chamber120. The treatment chamber 140 of one or more embodiments comprises anannealing chamber. The annealing chamber can be a furnace annealingchamber or a rapid thermal annealing chamber, or a different chamberconfigured to hold a wafer at a predetermined temperature and pressureand provide a flow of gas to the chamber.

In one or more embodiments, the processing platform further comprises asecond batch processing chamber 130 connected to a third side 113 of thecentral transfer station 110. The second batch processing chamber 130can be configured similarly to the first batch processing chamber 120,or can be configured to perform a different process or to processdifferent numbers of substrates.

The second batch processing chamber 130 can be the same as the firstbatch processing chamber 120 or different. In one or more embodiments,the first batch processing chamber 120 and the second batch processingchamber 130 are configured to perform the same process with the samenumber of wafers in the same batch time so that x (the number of wafersin the first batch processing chamber 120) and y (the number of wafersin the second batch processing chamber 130) are the same and the firstbatch time and second batch time (of the second batch processing chamber130) are the same. In one or more embodiments, the first batchprocessing chamber 120 and the second batch processing chamber 130 areconfigured to have one or more of different numbers of wafers (x notequal to y), different batch times, or both.

In the embodiments shown in FIG. 1, the processing platform 100 includesa second treatment chamber 150 connected to a fourth side 114 of thecentral transfer station 110. The second treatment chamber 150 can bethe same as the treatment chamber 140 or different.

The processing platform 100 can include a controller 195 connected tothe robot 117 (the connection is not shown). The controller 195 can beconfigured to move wafers between the treatment chamber 140 and thefirst batch processing chamber 120 with a first arm 118 of the robot117. In one or more embodiments, the controller 195 is also configuredto move wafers between the second treatment chamber 150 and the secondbatch processing chamber 130 with a second arm 119 of the robot 117.

In one or more embodiments, the controller 195 is connected to thesusceptor assembly 240 and the gas distribution assembly 220 of aprocessing chamber 200. The controller 195 can be configured to rotatethe susceptor assembly 240 about a central axis. The controller can alsobe configured to control the gas flows in the gas ports 225, 235, 245,255. In one or more embodiments, the first reactive gas port 225provides a flow of a metal precursor. In one or more embodiments, thesecond reactive gas port 235 provides a flow of a reactant. In one ormore embodiments, other gas ports (not labeled) may provide a flow ofplasma. The first reactive gas port 225, the second reactive gas port235 and the other reactive gas ports (not labeled) may be arranged inany processing order.

The processing platform 100 can also include a first buffer station 151connected to a fifth side 115 of the central transfer station 110 and/ora second buffer station 152 connected to a sixth side 116 of the centraltransfer station 110. The first buffer station 151 and second bufferstation 152 can perform the same or different functions. For example,the buffer stations may hold a cassette of wafers which are processedand returned to the original cassette, or the first buffer station 151may hold unprocessed wafers which are moved to the second buffer station152 after processing. In one or more embodiments, one or more of thebuffer stations are configured to pre-treat, pre-heat or clean thewafers before and/or after processing.

In one or more embodiments, the controller 195 is configured to movewafers between the first buffer station 151 and one or more of thetreatment chamber 140 and the first batch processing chamber 120 usingthe first arm 118 of the robot 117. In one or more embodiments, thecontroller 195 is configured to move wafers between the second bufferstation 152 and one or more of the second treatment chamber 150 or thesecond batch processing chamber 130 using the second arm 119 of therobot 117.

The processing platform 100 may also include one or more slit valves 160between the central transfer station 110 and any of the processingchambers. In the embodiments shown, there is a slit valve 160 betweeneach of the processing chambers 120, 130, 140, 150 and the centraltransfer station 110. The slit valves 160 can open and close to isolatethe environment within the processing chamber from the environmentwithin the central transfer station 110. For example, if the processingchamber will generate plasma during processing, it may be helpful toclose the slit valve for that processing chamber to prevent stray plasmafrom damaging the robot in the transfer station.

In one or more embodiments, the processing chambers are not readilyremovable from the central transfer station 110. To allow maintenance tobe performed on any of the processing chambers, each of the processingchambers may further include a plurality of access doors 170 on sides ofthe processing chambers. The access doors 170 allow manual access to theprocessing chamber without removing the processing chamber from thecentral transfer station 110. In the embodiments shown, each side ofeach of the processing chamber, except the side connected to thetransfer station, have an access door 170. The inclusion of so manyaccess doors 170 can complicate the construction of the processingchambers employed because the hardware within the chambers would need tobe configured to be accessible through the doors.

The processing platform of one or more embodiments includes a water box180 connected to the central transfer station 110. The water box 180 canbe configured to provide a coolant to any or all of the processingchambers. Although referred to as a “water” box, those skilled in theart will understand that any coolant can be used.

In one or more embodiments, the size of the processing platform 100allows for the connection to house power through a single powerconnector 190. The single power connector 190 attaches to the processingplatform 100 to provide power to each of the processing chambers and thecentral transfer station 110.

In one or more embodiments, the processing platform 100 can be connectedto a factory interface 102 to allow wafers or cassettes of wafers to beloaded into the processing platform 100. A robot 103 within the factoryinterface 102 can be moved the wafers or cassettes into and out of thebuffer stations 151, 152. The wafers or cassettes can be moved withinthe processing platform 100 by the robot 117 in the central transferstation 110. In one or more embodiments, the factory interface 102 is atransfer station of another cluster tool.

In one or more embodiments, the processing platform 100 or first batchprocessing chamber 120 is connected to a controller. The controller canbe the same controller 195 or a different controller. The controller canbe coupled to the susceptor assembly and the gas distribution assemblyof the first batch processing chamber 120 and has one or moreconfigurations. The configurations can include, but are not limited to,a first configuration to rotate the susceptor assembly about the centralaxis, a second configuration to provide a flow of a metal precursor to aprocess region, a third configuration to provide a flow of a reactant toa process region, a fourth configuration to provide a plasma in aprocess region.

One or more embodiments are directed to a non-transitory computerreadable medium including instructions, that, when executed by acontroller of a processing chamber, causes the processing chamber toperform operations of: exposing a substrate surface to a halogencatalyst to form an activated substrate surface; and flowing a precursorinto a processing volume of the processing chamber having the substrate,the precursor having general formula (I): M-L₁(L₂)_(y), wherein M is ametal, L₁ is an aromatic ligand, L₂ is an aliphatic ligand, and y is anumber in the range of from 2 to 8, wherein the L₂ comprises1,5-hexdiene, 1,4-hexadiene, and less than 5% of 1,3-hexadiene.

FIG. 7 illustrates a process flow diagram depicting a generalized methodfor forming a metal film on a substrate in accordance with one or moreembodiments of the disclosure. The method 700 generally begins atoperation 702, where a substrate upon which a metal film is to be formedis placed into a processing chamber. As used herein, a “substratesurface” refers to any substrate surface upon which a layer may beformed. The substrate surface may have one or more features formedtherein, one or more layers formed thereon, and combinations thereof. Inone or more embodiments, the substrate (or substrate surface) may bepretreated prior to the deposition of the metal film, for example, bypolishing, etching, reduction, oxidation, halogenation, hydroxylation,annealing, baking, or the like.

In one or more embodiments, the substrate may be any substrate capableof having material deposited thereon, such as a silicon substrate, aIII-V compound substrate, a silicon germanium (SiGe) substrate, anepi-substrate, a silicon-on-insulator (SOI) substrate, a displaysubstrate such as a liquid crystal display (LCD), a plasma display, anelectro luminescence (EL) lamp display, a solar array, solar panel, alight emitting diode (LED) substrate, a semiconductor wafer, or thelike. In one or more embodiments, one or more additional layers may bedisposed on the substrate such that the metal film may be, at leastpartially, formed thereon. For example, in one or more embodiments, alayer comprising a metal, a nitride, an oxide, or the like, orcombinations thereof may be disposed on the substrate and may have themetal film formed upon such layer or layers.

In one or more embodiments, at operation 703, the substrate isoptionally exposed to a blocking compound. This process step isdescribed in more detail below and may be useful for controlling theselectivity of the deposition process on a substrate comprising both ametal surface and a dielectric surface.

In one or more embodiments, at operation 704, a metal film is formed onthe substrate. In one or more embodiments, the metal film may be formedvia a cyclical deposition process, such as atomic layer deposition(ALD), or the like. In one or more embodiments, the forming of a metalfilm via a cyclical deposition process may generally comprise exposingthe substrate to two or more process gases separately. In time-domainALD embodiments, exposure to each of the process gases are separated bya time delay/pause to allow the components of the process gases toadhere and/or react on the substrate surface. Alternatively, or incombination, in one or more embodiments, a purge may be performed beforeand/or after the exposure of the substrate to the process gases, whereinan inert gas is used to perform the purge. For example, a first processgas may be provided to the process chamber followed by a purge with aninert gas. Next, a second process gas may be provided to the processchamber followed by a purge with an inert gas. In one or moreembodiments, the inert gas may be continuously provided to the processchamber and the first process gas may be dosed or pulsed into theprocess chamber followed by a dose or pulse of the second process gasinto the process chamber. In such embodiments, a delay or pause mayoccur between the dose of the first process gas and the second processgas, allowing the continuous flow of inert gas to purge the processchamber between doses of the process gases.

In spatial ALD embodiments, exposure to each of the process gases occurssimultaneously to different parts of the substrate so that one part ofthe substrate is exposed to the first reactive gas while a differentpart of the substrate is exposed to the second reactive gas (if only tworeactive gases are used). The substrate is moved relative to the gasdelivery system so that each point on the substrate is sequentiallyexposed to both the first and second reactive gases. In any embodimentsof a time-domain ALD or spatial ALD process, the sequence may berepeated until a predetermined layer thickness is formed on thesubstrate surface.

A “pulse” or “dose” as used herein is intended to refer to a quantity ofa source gas that is intermittently or non-continuously introduced intothe process chamber. The quantity of a particular compound within eachpulse may vary over time, depending on the duration of the pulse. Aparticular process gas may include a single compound or amixture/combination of two or more compounds, for example, the processgases described below.

The durations for each pulse/dose are variable and may be adjusted toaccommodate, for example, the volume capacity of the processing chamberas well as the capabilities of a vacuum system coupled thereto.Additionally, the dose time of a process gas may vary according to theflow rate of the process gas, the temperature of the process gas, thetype of control valve, the type of process chamber employed, as well asthe ability of the components of the process gas to adsorb onto thesubstrate surface. Dose times may also vary based upon the type of layerbeing formed and the geometry of the device being formed. A dose timeshould be long enough to provide a volume of compound sufficient toadsorb/chemisorb onto substantially the entire surface of the substrateand form a layer of a process gas component thereon.

In one or more embodiments, the process of forming the metal film atoperation 704 may begin by exposing the substrate to a first reactivegas. In one or more embodiments, the first reactive gas comprises ahalogen catalyst. In other embodiments, the first reactive gas comprisesan alkyl halide catalyst.

As used herein, the term “halide” refers to a binary phase, of which onepart is a halogen atom and the other part is an element or radical thatis less electronegative than the halogen, to make a fluoride, chloride,bromide, iodide, or astatide compound. A halide ion is a halogen atombearing a negative charge. As known to those of skill in the art, ahalide anion includes fluoride (F—), chloride (Cl—), bromide (Br—),iodide (I—), and astatide (At—).

Unless otherwise indicated, the term “lower alkyl,” “alkyl,” or “alk” asused herein alone or as part of another group includes both straight andbranched chain hydrocarbons, containing 1 to 20 carbons, in the normalchain, such as methyl, ethyl, propyl, isopropyl, butyl, t-butyl,isobutyl, pentyl, hexyl, isohexyl, heptyl, 4,4-dimethylpentyl, octyl,2,2,4-trimethyl-pentyl, nonyl, decyl, undecyl, dodecyl, the variousbranched chain isomers thereof, and the like. Such groups may optionallyinclude up to 1 to 4 substituents.

In one or more embodiments, the process of forming the metal film atoperation 704 begins by exposing the substrate to a first reactive gascomprising an alkyl halide catalyst. In one or more embodiments, thefirst reactive gas comprises an alkyl halide catalyst and is exposed tothe substrate for a first period of time, as shown at operation 706.

In one or more embodiments, the alkyl halide catalyst may be anysuitable reactant to adsorb a layer of halogen on the substrate forlater reaction. In one or more embodiments, the alkyl halide catalystcomprises carbon and halogen. In one or more embodiments, the halogencomprises bromine or iodine. In one or more embodiments, the halogen isinsoluble in the metal film. As used in this regard, a halogen which isinsoluble in a metal film comprises less than or equal to about 2%, lessthan or equal to about 1%, or less than or equal to about 0.5% of themetal film on an atomic basis. In one or more embodiments, the alkylhalide catalyst has the general formula R—X, wherein R is an alkyl,alkenyl, aryl, or other carbonaceous group. In one or more embodiments,R comprises one to two, one to four, or one to six carbon atoms.

In one or more embodiments, the alkyl halide catalyst comprises orconsists essentially of iodoethane (H₅C₂I) or diiodomethane (CH₂I₂). Asused in this regard, an alkyl halide catalyst which consists essentiallyof a stated species comprises greater than 95%, 98%, 99% or 99.5% of thestated species on a molar basis, excluding any inert diluent gases.

In one or more embodiments, the alkyl halide catalyst is delivered tothe processing chamber as an alkyl halide catalyst containing gas. Inone or more embodiments, the alkyl halide catalyst containing gas may beprovided in one or more pulses or continuously. In one or moreembodiments, the flow rate of the alkyl halide catalyst containing gascan be any suitable flow rate including, but not limited to, flow ratesis in the range of about 1 to about 5000 sccm, or in the range of about2 to about 4000 sccm, or in the range of about 3 to about 3000 sccm orin the range of about 5 to about 2000 sccm. The alkyl halide catalystcontaining gas can be provided at any suitable pressure including, butnot limited to, a pressure in the range of about 5 mTorr to about 25Torr, or in the range of about 100 mTorr to about 20 Torr, or in therange of about 5 Torr to about 20 Torr, or in the range of about 50mTorr to about 2000 mTorr, or in the range of about 100 mTorr to about1000 mTorr, or in the range of about 200 mTorr to about 500 mTorr.

The period of time that the substrate is exposed to the alkyl halidecatalyst containing gas may be any suitable amount of time necessary toallow the alkyl halide catalyst to form an adequate adsorption layeratop the substrate surface(s). For example, the process gas may beflowed into the process chamber for a period of about 0.1 seconds toabout 90 seconds. In some time-domain ALD processes, the alkyl halidecatalyst containing gas is exposed the substrate surface for a time inthe range of about 0.1 sec to about 90 sec, or in the range of about 0.5sec to about 60 sec, or in the range of about 1 sec to about 30 sec, orin the range of about 2 sec to about 25 sec, or in the range of about 3sec to about 20 sec, or in the range of about 4 sec to about 15 sec, orin the range of about 5 sec to about 10 sec.

In one or more embodiments, an inert gas may additionally be provided tothe process chamber at the same time as the alkyl halide catalystcontaining gas. The inert gas may be mixed with the alkyl halidecatalyst containing gas (e.g., as a diluent gas) or be providedseparately and can be pulsed or of a constant flow. In one or moreembodiments, the inert gas is flowed into the processing chamber at aconstant flow in the range of about 1 to about 10000 sccm. The inert gasmay be any inert gas, for example, such as argon (Ar), helium (He), neon(Ne), or combinations thereof.

The temperature of the substrate during deposition can be controlled,for example, by setting the temperature of the substrate support orsusceptor. In one or more embodiments, the substrate is held at atemperature in the range of about 0° C. to about 600° C., or in therange of about 25° C. to about 500° C., or in the range of about 50° C.to about 450° C., or in the range of about 100° C. to about 400° C., orin the range of about 200° C. to about 400° C., or in the range of about250° C. to about 350° C. In one or more embodiments, the substrate ismaintained at a temperature below the decomposition temperature of themetal precursor. In one or more embodiments, the substrate is maintainedat a temperature below the decomposition temperature of the alkyl halidecatalyst. In one or more embodiments, the substrate is maintained at atemperature between the decomposition temperature of the alkyl halidecatalyst and the decomposition temperature of the metal precursor.

In one or more embodiments, the substrate is maintained at a temperatureless than or equal to about 400° C., or less than or equal to about 350°C., or less than about 300° C. In one or more embodiments, the substrateis maintained at a temperature greater than or equal to about 250° C.,or greater than or equal to about 300° C., or greater than about 350° C.In one or more embodiments, the substrate is maintained at a temperatureof about 280° C.

In addition to the foregoing, additional process parameters may beregulated while exposing the substrate to the alkyl halide catalystcontaining gas. For example, in one or more embodiments, the processchamber may be maintained at a pressure of about 0.2 to about 100 Torr,or in the range of about 0.3 to about 90 Torr, or in the range of about0.5 to about 80 Torr, or in the range of about 1 to about 50 Torr.

Next, at 708, the process chamber (especially in time-domain ALD) may bepurged using an inert gas. (This may not be needed in spatial ALDprocesses as there are gas curtains separating the reactive gases.) Theinert gas may be any inert gas, for example, such as argon, helium,neon, or the like. In one or more embodiments, the inert gas may be thesame, or alternatively, may be different from the inert gas provided tothe process chamber during the exposure of the substrate to the alkylhalide catalyst containing gas at operation 706. In embodiments wherethe inert gas is the same, the purge may be performed by diverting thefirst process gas from the process chamber, allowing the inert gas toflow through the process chamber, purging the process chamber of anyexcess first process gas components or reaction byproducts. In one ormore embodiments, the inert gas may be provided at the same flow rateused in conjunction with the first process gas, described above, or inone or more embodiments, the flow rate may be increased or decreased.For example, in one or more embodiments, the inert gas may be providedto the process chamber at a flow rate of about 0 to about 10000 sccm topurge the process chamber. In spatial ALD, purge gas curtains aremaintained between the flows of reactive gases and purging the processchamber may not be necessary. In one or more embodiments of a spatialALD process, the process chamber or region of the process chamber may bepurged with an inert gas.

The flow of inert gas may facilitate removing any excess first processgas components and/or excess reaction byproducts from the processchamber to prevent unwanted gas phase reactions of the first and secondprocess gases.

Next, at operation 710, the substrate is exposed to a second process gasfor a second period of time. The second process gas comprises aprecursor which reacts with the adsorbed layer of halogen on thesubstrate surface to deposit a metal film. In one or more embodiments,the second reactive gas may also be referred to as the precursor gas.

In one or more embodiments, the precursor may be any suitable precursorto react with the adsorbed halogen layer on the substrate. In one ormore embodiments, the precursor comprises a metal and at least twoligands. In one or more embodiments, the metal comprises one or moremetal atoms.

In one or more embodiments, the metal is selected from one or more of Inone or more embodiments, the metal is selected from molybdenum (Mo),ruthenium (Ru), cobalt (Co), copper (Cu), platinum (Pt), nickel (Ni), ortungsten (W). In other embodiments, the metal is selected from ruthenium(Ru), tungsten (W), or molybdenum (Mo). In one or more specificembodiments, the metal comprises ruthenium (Ru).

In one or more embodiments, the precursor comprises multiple, at leasttwo, organic ligands. In one or more embodiments, the precursorcomprises a metal, M, and an aromatic ligand L₁, and an aliphaticligand, L₂. In one or more specific embodiments, the precursor comprisesruthenium, an aromatic ligand L₁, and an aliphatic ligand, L₂. In someembodiments, the precursor comprises more than one aliphatic ligand, L₂.In one or more embodiments, the precursor comprises from two to eightaliphatic ligands, L₂. When more than one aliphatic ligand, L₂, ispresent, the L₂ ligands may be the same or different.

In one or more embodiments, the precursor is of the general formula (I):M-L₁(L₂)_(y), where M is a metal, L₁ is an aromatic ligand, L₂ is analiphatic ligand, and y is a number in the range of from 2 to 8,including from 2 to 6, and from 2 to 5.

In one or more embodiments, the aromatic ligand, L₁, comprises a pielectron system selected from η², η⁴, η⁶, and η⁸. In some embodiments,the aromatic ligand, L₁, comprises 1-methyl-4-isopropylbenzene.

In one or more embodiments, the aliphatic ligand, L₂, comprises analiphatic diene. In one or more embodiments, the aliphatic ligand, L₂,comprises one or more of 1,5-hexadiene, 1,4-hexadiene, 1,3-hexadiene. Inone or more embodiments, the aliphatic ligand, L₂, comprises less than5% of 1,3-hexadiene, including less than about 4% of 1,3-hexadiene, lessthan about 3% 1,3-hexadiene, less than about 2% 1,3-hexadiene, and lessthan about 1% 1,3-hexadience.

In one or more embodiments, the method comprises forming a film on asubstrate surface by exposing the substrate surface to a precursor ofgeneral formula (I): M-L₁(L₂)_(y), wherein M is a metal, L₁ is anaromatic ligand, L₂ is an aliphatic ligand, and y is a number in therange of from 2 to 8, wherein L₂ comprises 1,5-hexdiene, 1,4-hexadiene,and less than 5% of 1,3-hexadiene.

In one or more embodiments, the precursor comprises a metal, M, and anaromatic ligand L₁, and at least two aliphatic ligands, L₂. In one ormore embodiments, the aliphatic ligand, L₂, further comprises anasymmetric cyclic diene. In one or more embodiments, the asymmetriccyclic diene comprises one or more of 3-(2-propenyl)-cyclohexene,1-(2-propenyl)-cyclohexene, 1,3-propadiene-cyclohexane, and1,2-divinylcyclohexane.

Without intending to be bound by theory, it is thought that controllingthe ratio of hexadiene isomers in a mixture of L₂ aliphatic ligandsproduces a gap fill with superior performance. Thus, in one or moreembodiments, the ratio of 1,5-hexadiene to other L₂ aliphatic ligandspresent in the precursor should be greater than 50%. In someembodiments, the ratio of 1,5-hexadiene to other L₂ aliphatic ligandspresent in the precursor is in a range of from about 50:50 to about60:40. In one or more embodiments, y is a number in a range of from 2 to6, and the ratio of 1,5-hexadiene to the sum the 1,4-hexadiene,1,3-hexadiene, and the asymmetric cyclic diene is in a range of fromabout 50:50 to about 60:40. In one or more embodiments, the asymmetriccyclic diene comprises one or more of 3-(2-propenyl)-cyclohexene,1-(2-propenyl)-cyclohexene, 1,3-propadiene-cyclohexane, and1,2-divinylcyclohexane. Accordingly, in one or more embodiments, y is anumber in a range of from 2 to 6, and the ratio of 1,5-hexadiene to thesum 1,4-hexadiene, 1,3-hexadiene, 3-(2-propenyl)-cyclohexene,1-(2-propenyl)-cyclohexene, 1,3-propadiene-cyclohexane, and1,2-divinylcyclohexane is in a range of from about 50:50 to about 60:40.

In one or more embodiments, the metal of the precursor corresponds tothe metal of the deposited metal film. In one or more embodiments, themetal is selected from molybdenum (Mo), ruthenium (Ru), cobalt (Co),copper (Cu), platinum (Pt), nickel (Ni), or tungsten (W). In one or moreembodiments, the metal of the precursor has an oxidation state of 0.Stated differently, in one or more embodiments, the metal precursorcomprises a zero-valent metal complex.

Additional process parameters may be regulated while exposing thesubstrate to the precursor gas. For example, in one or more embodiments,the process chamber may be maintained at a pressure of about 0.2 toabout 100 Torr, or in the range of about 0.3 to about 90 Torr, or in therange of about 0.5 to about 80 Torr, or in the range of about 1 to about50 Torr.

In one or more embodiments, the precursor is delivered to the processingchamber as a precursor gas. The precursor gas may be provided in one ormore pulses or continuously. The flow rate of the precursor gas can beany suitable flow rate including, but not limited to, flow rates is inthe range of about 1 to about 5000 sccm, or in the range of about 2 toabout 4000 sccm, or in the range of about 3 to about 3000 sccm or in therange of about 5 to about 2000 sccm. The precursor gas can be providedat any suitable pressure including, but not limited to, a pressure inthe range of about 5 mTorr to about 25 Torr, or in the range of about100 mTorr to about 20 Torr, or in the range of about 5 Torr to about 20Torr, or in the range of about 50 mTorr to about 2000 mTorr, or in therange of about 100 mTorr to about 1000 mTorr, or in the range of about200 mTorr to about 500 mTorr.

In one or more embodiments, the period of time that the substrate isexposed to the metal precursor gas may be any suitable amount of timenecessary to allow the metal precursor to react with the adsorbedhalogen on the substrate surface. For example, the process gas may beflowed into the process chamber for a period of about 0.1 seconds toabout 90 seconds. In some time-domain ALD processes, the precursor gasis exposed the substrate surface for a time in the range of about 0.1sec to about 90 sec, or in the range of about 0.5 sec to about 60 sec,or in the range of about 1 sec to about 30 sec, or in the range of about2 sec to about 25 sec, or in the range of about 3 sec to about 20 sec,or in the range of about 4 sec to about 15 sec, or in the range of about5 sec to about 10 sec.

In one or more embodiments, an inert gas may additionally be provided tothe process chamber at the same time as the precursor gas. The inert gasmay be mixed with the precursor gas (e.g., as a diluent gas) or beprovided separately and can be pulsed or of a constant flow. In one ormore embodiments, the inert gas is flowed into the processing chamber ata constant flow in the range of about 1 to about 10000 sccm. The inertgas may be any inert gas, for example, such as argon, helium, neon, orcombinations thereof.

In one or more embodiments, at operation 712, the process chamber may bepurged using an inert gas. The inert gas may be any inert gas, forexample, such as argon (Ar), helium (He), neon (Ne), or the like. In oneor more embodiments, the inert gas may be the same, or alternatively,may be different from the inert gas provided to the process chamberduring previous process routines. In embodiments where the inert gas isthe same, the purge may be performed by diverting the second process gasfrom the process chamber, allowing the inert gas to flow through theprocess chamber, purging the process chamber of any excess secondprocess gas components or reaction byproducts. In one or moreembodiments, the inert gas may be provided at the same flow rate used inconjunction with the second process gas, described above, or in one ormore embodiments, the flow rate may be increased or decreased. Forexample, in one or more embodiments, the inert gas may be provided tothe process chamber at a flow rate of greater than 0 to about 10,000sccm to purge the process chamber.

While the generic embodiments of the processing method shown in FIG. 7includes only two pulses of reactive gases, it will be understood thatthis is merely exemplary and that additional pulses of reactive gasesmay be used. In one or more embodiments, the method is performed withoutthe use of an oxygen-containing reactive gas. The sub processes ofoperation 704 comprise a cycle. A cycle may be performed in any order aslong as the reactive gases are separated by a purge of the processingchamber. In one or more embodiments, the metal film is deposited at rategreater than or equal to about 0.2 Å/cycle, greater than or equal toabout 0.3 Å/cycle, greater than or equal to about 0.4 Å/cycle, greaterthan or equal to about 0.5 Å/cycle, greater than or equal to about 0.6Å/cycle, greater than or equal to about 0.7 Å/cycle, greater than orequal to about 0.8 Å/cycle, greater than or equal to about 0.9 Å/cycle,greater than or equal to about 1.0 Å/cycle, or greater than or equal toabout 1.2 Å/cycle.

The deposition process is performed as a thermal process without the useof plasma reactants. Stated differently, in one or more embodiments, themethod is performed without plasma.

In one or more embodiments, at decision point 714, it is determinedwhether the metal film has achieved a predetermined thickness. If thepredetermined thickness has not been achieved, the method 700 returns tooperation 704 to continue forming the metal film until the predeterminedthickness is reached. Once the predetermined thickness has been reached,the method 700 can either end or proceed to operation 716 for optionalfurther processing (e.g., bulk deposition of another metal film). In oneor more embodiments, the metal film may be deposited to form a totallayer thickness of about 10 Å to about 10,000 Å, or in one or moreembodiments, about 10 Å to about 1000 Å, or in one or more embodiments,about 50 Å to about 5,000 Å.

In one or more embodiments, the metal layer comprises greater than orequal to about 75 atomic % ruthenium, or greater than or equal to about80 atomic % ruthenium, or greater than or equal to about 85 atomic %ruthenium, or greater than or equal to about 90 atomic % ruthenium, orgreater than or equal to about 95 atomic % ruthenium.

In one or more embodiments, the metal layer comprises less than or equalto about 10 atomic % oxygen, or less than or equal to about 9 atomic %oxygen, or less than or equal to about 8 atomic % oxygen, or less thanor equal to about 7 atomic % oxygen, or less than or equal to about 6atomic % oxygen, or less than or equal to about 5 atomic % oxygen, orless than or equal to about 4 atomic % oxygen, or less than or equal toabout 3 atomic % oxygen.

In one or more embodiments, the metal layer comprises in the range ofabout 0.02 to about 5 atomic % iodine, or less than or equal to about 1atomic % iodine.

In one or more embodiments, the metal layer comprises less than or equalto about 20 atomic % carbon, or less than or equal to about 15 atomic %carbon, or less than or equal to about 10 atomic % carbon, or less thanor equal to about 5 atomic % carbon.

In one or more embodiments, the metal layer comprises greater than orequal to about 90 atomic % ruthenium, less than or equal to about 3atomic % oxygen, less than or equal to about 1 atomic % iodine and lessthan or equal to about 10 atomic % carbon.

In one or more embodiments, the metal layer has a resistivity of lessthan or equal to about 40 μohm-cm, or less than or equal to about 35μohm-cm, or less than or equal to about 30 μohm-cm, or less than orequal to about 25 μohm-cm, or less than or equal to about 20 μohm-cm. InOne or more embodiments, the metal layer comprises ruthenium and has aresistivity of less than or equal to about 40 μohm-cm, or less than orequal to about 35 μohm-cm, or less than or equal to about 30 μohm-cm, orless than or equal to about 25 μohm-cm, or less than or equal to about20 μohm-cm.

In one or more embodiments, the metal film is further processed byannealing the metal film. Without intending to be bound by theory, it isbelieved that annealing the film at a high temperature under an argon(Ar) or hydrogen (H₂) atmosphere reduces carbon and halogen impuritiesin the metal film. In one or more embodiments, the metal film isannealed under an atmosphere comprising argon or hydrogen gas (H₂) toreduce the atomic concentration of carbon and/or halogen impurities.

The metal film deposited by one or more embodiments is smoother than thefilms deposited by known oxygen-based deposition processes. In one ormore embodiments, the metal film has a surface roughness of less than orequal to about 10%, less than or equal to about 8%, less than or equalto about 5%, or less than or equal to about 2%, of a thickness of themetal film.

The purity of the metal film is high. In one or more embodiments, themetal film has a carbon content less than or equal to about 2%, lessthan or equal to about 1%, or less than or equal to about 0.5% carbon onan atomic basis. In one or more embodiments, the metal film has ahalogen content less than or equal to about 1% or less than or equal toabout 0.5% halogen on an atomic basis. In one or more embodiments, themetal film has a purity of greater than or equal to about 95%, greaterthan or equal to about 97%, greater than or equal to about 99%, greaterthan or equal to about 99.5%, or greater than or equal to about 99.9%metal atoms on an atomic basis.

One or more embodiments of the disclosure selectively deposit a firstmetal film on a second metal surface over a first dielectric surface.These methods are similar to method 700 as described above, except thatthe substrate provided comprises a first dielectric surface and a secondmetal surface. The first metal (of the metal film) and the second metal(of the substrate surface) may be the same metal or may be differentmetals. In one or more embodiments, the first metal is molybdenum (Mo),ruthenium (Ru), cobalt (Co), copper (Cu), platinum (Pt), nickel (Ni), ortungsten (W), while the second metal is tungsten (W), cobalt (Co), orcopper (Cu).

In one or more embodiments, the first dielectric surface may be formedfrom any suitable dielectric material. In one or more embodiments, thedielectric material comprises nitrogen or oxygen atoms. Without beingbound by theory, it is believed that these materials react with thealkyl halide catalyst and prevents the halogen from adsorbing onto thesubstrate surface so as to catalyze the reaction with the metalprecursor. Accordingly, little, if any, metal film is formed on thedielectric surface.

In one or more embodiments, the deposition temperature is below thedecomposition temperature of the alkyl halide catalyst. Again, withoutbeing bound by theory, it is believed that if the alkyl halide catalystdecomposes, the halogen will be available for reaction with the metalprecursor on all surfaces (regardless of composition), leading to metalfilm deposition on all substrate surfaces, including the dielectricsurface. In one or more embodiments, the deposition temperature is at orabove the decomposition temperature of the alkyl halide catalyst.

One or more embodiments of the disclosure selectively deposit a firstmetal film on a first dielectric surface over a second metal surface.These methods are similar to method 700 as described above, except thatthe substrate provided comprises a first dielectric surface and a secondmetal surface and the substrate is exposed to a blocking compound atoperation 703.

In one or more embodiments, at operation 703, a substrate comprising atleast a second metal surface and a first dielectric surface is exposedto a blocking compound. The blocking compound may be any suitablecompound for blocking deposition on the second metal surface. In one ormore embodiments, the blocking compound comprises at least one triplebond between two carbon atoms. Stated differently, in one or moreembodiments, the blocking compound comprises an alkyne. In one or moreembodiments, the blocking compound has the general formula of R′≡R″. Inone or more embodiments, R′ and R″ are identical. In one or moreembodiments, R′ and/or R″ are an alkyl or other carbonaceous group. Inone or more embodiments, the blocking compound comprises 4-12 carbonatoms. In one or more embodiments, R′ and/or R″ are linear. In One ormore embodiments, R′ and/or R″ are branched. In one or more embodiments,the blocking compound comprises 3-hexyne.

The first metal (of the metal film) and the second metal (of thesubstrate surface) may be the same metal or may be different metals. Inone or more embodiments, the first metal is molybdenum (Mo), ruthenium(Ru), cobalt (Co), copper (Cu), platinum (Pt), nickel (Ni), or tungsten(W), while the second metal is tungsten (W), cobalt (Co), or copper (Cu)

The first dielectric surface may be formed from any suitable dielectricmaterial. In one or more embodiments, the dielectric material comprisesnitrogen or oxygen atoms.

As mentioned previously, in one or more embodiments, the depositiontemperature is at or above the decomposition temperature of the alkylhalide catalyst. In one or more embodiments, the deposition temperatureis greater than or equal to about 250° C., greater than or equal toabout 260° C., greater than or equal to about 270° C., greater than orequal to about 280° C., greater than or equal to about 290° C., orgreater than or equal to about 300° C. In one or more embodiments, thedeposition temperature is in the range of about 250° C. to about 450°C., or in the range of about 300° C. to about 400° C. In one or moreembodiments, the deposition temperature is about 350° C.

As stated previously, without being bound by theory, it is believed thatthese materials react with the alkyl halide catalyst and prevent thehalogen from adsorbing onto the substrate surface so as to catalyze thereaction with the metal precursor. Accordingly, little, if any, metalfilm is formed on the dielectric surface.

In one or more embodiments, however, when the deposition temperature isabove the decomposition temperature of the alkyl halide catalyst, thehalogen atoms are deposited on the entire substrate surface, therebyallowing deposition on the dielectric surface. In one or moreembodiments, the metal surface is blocked by the blocking compound, soas to allow little, if any, metal film to be formed on the metalsurface. Accordingly, deposition of the metal film is selective to thedielectric surface over the metal surface,

In general terms, according to one or more embodiments, the depositionof highly pure metal films can be understood as follows. A substrate,maintained at a deposition temperature, is exposed to an alkyl halidecatalyst (R—X) to adsorb R and X on the substrate, where R is acarbonaceous group and X is a halogen. In one or more embodiments, X isa halogen selected from one or more of fluorine (F), chlorine (Cl),bromine (Br), iodine (I), and astatine (At). R is desorbed in the formof R—R or R⁻, leaving X adsorbed on the substrate. The substrate isexposed to a precursor, M-L₁(L₂)_(y), where M is the metal and L₁ is anaromatic ligand, L₂ is an aliphatic ligand, and y is a number in therange of from 2 to 8, including from 2 to 6, and from 2 to 5. In one ormore embodiments, L₂ comprises 1,5-hexdiene, 1,4-hexadiene, and lessthan 5% of 1,3-hexadiene. In other embodiments, the aliphatic ligand,L₂, further comprises an asymmetric cyclic diene. In some embodiments,the asymmetric cyclic diene comprises one or more of3-(2-propenyl)-cyclohexene, 1-(2-propenyl)-cyclohexene,1,3-propadiene-cyclohexane, and 1,2-divinylcyclohexane.

In one or more embodiments, M-L₁(L₂)_(y) reacts with the adsorbed X toform M-X on the substrate surface, liberating L₁(L₂)_(y). M-X reactswith other M-X moieties on the substrate to form M-M. This reaction mayproduce either X-X or X. X-X may be desorbed and purged. X⁻ may remainon the surface to further react with M-L₁(L₂)_(y).

In one or more embodiments, this general mechanism relies on severalpremises. First, X is not soluble in M. Without intending to be bound bytheory, the insolubility of X confers that X will not be found inappreciable quantity within the final metal film. While it is possibleto ignore this premise (e.g., utilizing a halogen soluble in M), using ahalogen (X) which is soluble in M is believed to provide metal filmswith lower purity. Second, in terms of bond strength, M-L₁(L₂)_(y) isweaker than M-X which is weaker than M-M. Again, without intending to bebound by theory, these thermodynamic relationships ensure that thereactions identified above are thermodynamically favorable. Finally,M-L₁(L₂)_(y) is thermally stable at the deposition temperature. Stateddifferently, the thermal decomposition temperature of the metalprecursor is higher than the deposition temperature. The theory herestates that if the metal precursor decomposes, the deposited film willcontain an appreciable quantity of the precursor ligands L₁ and(L₂)_(y), typically seen as carbon impurities.

In one or more embodiments, it has been surprisingly found thatprocesses including precursors of general formula (I) M-L₁(L₂)_(y),alkyl halide catalysts and process conditions which meet all of theabove requirements deposit highly pure metal films and are particularlysuitable for seamless gap fill processes.

Additionally, it was surprisingly found that if the depositiontemperature is below the thermal decomposition temperature of thehalogen catalyst, e.g. alkyl halide catalyst, the deposition process isselective to metal surfaces over dielectric surfaces without requiringthe use of a blocking layer.

Further, it was surprisingly found that if the deposition temperature isat or above the thermal decomposition temperature of the halogencatalyst, e.g. alkyl halide catalyst, the deposition process can be madeselective by exposing the metal surface to a small alkyne blockingcompound.

One or more embodiments of the disclosure advantageously provide methodsof depositing conformal metal films on substrates comprising high aspectratio structures. As used in this regard, the term “conformal” meansthat the thickness of the metal film is uniform across the substratesurface. As used in this specification and the appended claims, the term“substantially conformal” means that the thickness of the metal filmdoes not vary by more than about 10%, 5%, 2%, 1%, or 0.5% relative tothe average thickness of the film. Stated differently a film which issubstantially conformal has a conformality of greater than about 90%,95%, 98%, 99% or 99.5%.

One or more embodiments of the disclosure are directed to memory devicescomprising a ruthenium conductive layer. In one or more embodiments, theruthenium conductive layer comprises greater than or equal to about 90at. % ruthenium, less than or equal to about 3 at. % oxygen, less thanor equal to about 1 at. % iodine and less than or equal to about 10 at.% carbon, and a resistivity less than or equal to about 40 μohm-cm.

In one or more embodiments, the ruthenium conductive layer is formed ona barrier layer. The barrier layer of one or more embodiments has athickness less than or equal to about 10 Å, 20 Å, 30 Å, 40 Å or 50 Å. Inone or more embodiments, the ruthenium conductive layer is formed on asubstrate without an intervening barrier layer.

The above disclosure relates to the deposition of metal films by asequential pulse of reactants. The following disclosure relates to thedeposition of metal films by a simultaneous or constant-flow process. Inone or more embodiments, the sequential pulse methods are ALD methods.In one or more embodiments, the simultaneous or constant-flow methodsare CVD methods. While the process steps differ, many of the reactantsand process parameters are similar.

FIG. 8 illustrates a process flow diagram depicting a generalized method800 for forming a metal film on a substrate in accordance with one ormore embodiments of the disclosure. FIG. 9 illustrates an exemplarysubstrate for processing in accordance with one or more embodiments ofthe disclosure. The method 800 generally begins at operation 810, wherea substrate 900 upon which a metal film is to be formed is placed into aprocessing chamber.

Referring to FIG. 9, an exemplary substrate 900 is shown. In one or moreembodiments, the substrate 900 has a substrate surface 905 with at leastone feature 910 therein. The feature 910 has a sidewall 912, 914 and abottom 916. In one or more embodiments, a dielectric material 920 formsthe sidewall 912, 914 and a metallic material 930 forms the bottom 916.

In one or more embodiments, the substrate 900 may undergo pre-processingsteps. At 815, the substrate may optionally have one or more layersformed on the substrate surface.

In one or more embodiments, a metal nitride liner is deposited in thefeature 910. In one or more embodiments, the metal nitride linercomprises titanium nitride. In one or more embodiments, the metalnitride liner has a thickness in a range of about 15 Å to about 40 Å. Inone or more embodiments, the metal nitride liner has a thickness ofabout 20 Å or about 30 Å.

In one or more embodiments, a seed layer is deposited on the substratesurface. In one or more embodiments, the seed layer is a conformallayer. In one or more embodiments, the seed layer is continuous. In oneor more embodiments, the thickness of the seed layer is in a range ofabout 1 nm to about 5 nm, or in a range of about 1 nm to about 4 nm. Inone or more embodiments, the seed layer comprises a ruthenium layerdeposited by a known atomic layer deposition method. In one or moreembodiments, the seed layer is deposited by an ALD cycle comprising aprecursor exposure and an alkyl halide catalyst exposure withintervening purges. In one or more embodiments, the seed layer isdeposited by an ALD cycle comprising a precursor exposure and an ammoniaplasma exposure with intervening purges.

In one or more embodiments, the precursor is of general formula (I):M-L₁(L₂)_(y), where M is a metal and L₁ is an aromatic ligand, L₂ is analiphatic ligand, and y is a number in the range of from 2 to 8,including from 2 to 6, and from 2 to 5. In one or more embodiments, thealiphatic ligand, L₂, comprises an aliphatic diene. In one or moreembodiments, the aliphatic ligand, L₂, comprises one or more of1,5-hexadiene, 1,4-hexadiene, 1,3-hexadiene. In one or more embodiments,the aliphatic ligand, L₂, comprises less than 5% of 1,3-hexadiene,including less than about 4% of 1,3-hexadiene, less than about 3%1,3-hexadiene, less than about 2% 1,3-hexadiene, and less than about 1%1,3-hexadience. In one or more embodiments, the precursor comprises ametal, M, and an aromatic ligand L₁, and at least two aliphatic ligands,L₂. In one or more embodiments, the aliphatic ligand, L₂, furthercomprises an asymmetric cyclic diene. In one or more embodiments, theasymmetric cyclic diene comprises one or more of3-(2-propenyl)-cyclohexene, 1-(2-propenyl)-cyclohexene,1,3-propadiene-cyclohexane, and 1,2-divinylcyclohexane.

In one or more embodiments, at operation 820, the substrate isoptionally exposed to a blocking compound. This process step isdescribed in more detail below and may be useful for controlling theselectivity of the deposition process on a substrate comprising both ametal surface and a dielectric surface.

In one or more embodiments, at 830, a metal film is formed on thesubstrate. The process of forming the metal film at operation 830 maybegin by soaking the substrate with a catalytic gas. In one or moreembodiments, the catalytic gas comprises an alkyl halide catalyst and isexposed to the substrate for a first period of time, as shown atoperation 840.

In one or more embodiments, the halogen catalyst, e.g. alkyl halidecatalyst, may be any suitable reactant to adsorb a layer on thesubstrate for later reaction. Stated differently, soaking the substratein the halogen catalyst, e.g. alkyl halide catalyst, forms an activatedsubstrate surface. The halogen catalyst, e.g. alkyl halide catalyst, isdescribed above and elsewhere herein.

In one or more embodiments, the halogen catalyst, e.g. alkyl halidecatalyst may be provided to the processing chamber in one or more pulsesor continuously. In one or more embodiments, the halogen catalyst, e.g.alkyl halide catalyst, is provided with an inert carrier gas and isreferred to the alkyl halide catalyst containing gas. The flow rate andpressure of the halogen catalyst, e.g. alkyl halide catalyst, or halogencatalyst, e.g. alkyl halide catalyst, containing gas can be any suitablevalues. Exemplary flow rates and pressures disclosed elsewhere hereinfor the halogen catalyst, e.g. alkyl halide catalyst, containing gas arealso applicable in this embodiment.

In one or more embodiments, the period of time that the substrate issoaked in the halogen catalyst, e.g. alkyl halide catalyst, may be anysuitable amount of time necessary to allow the halogen catalyst to forman adequate adsorption layer on the substrate surface(s). For example,the halogen catalyst may be allowed to soak the substrate for a periodof greater than about 3 seconds or greater than about 5 seconds. In oneor more embodiments, the soak period is in a range of about 3 seconds toabout 60 seconds.

In one or more embodiments, an inert gas may additionally be provided tothe process chamber at the same time as the halogen catalyst, e.g. alkylhalide catalyst, containing gas. The inert gas may be mixed with thehalogen catalyst (e.g., as a diluent gas) or be provided separately andcan be pulsed or of a constant flow. The inert gas may be any inert gas,for example, such as argon, helium, neon, or combinations thereof.

In one or more embodiments, at operation 850, the substrate is exposedto a second process gas for a second period of time. The second processgas comprises a metal precursor which reacts with the adsorbed layer ofalkyl halide catalyst or halogen on the substrate surface to deposit ametal film. The second reactive gas may also be referred to as the metalprecursor gas.

In one or more embodiments, the metal precursor may be any suitableprecursor to react with the adsorbed alkyl halide catalyst layer orhalogen layer on the substrate. Suitable metal precursors are describedelsewhere herein.

In one or more embodiments, the metal precursor is delivered to theprocessing chamber as a metal precursor gas. The metal precursor gas maybe provided in one or more pulses or continuously. The flow rate andpressure of the metal precursor gas can be any suitable flow rate andpressure. Exemplary values for flow rate and pressure are discussedelsewhere herein.

In one or more embodiments, the period of time that the substrate isexposed to the metal precursor gas may be any suitable amount of timenecessary to allow the metal precursor to react with the adsorbedhalogen on the substrate surface. For example, the process gas may beflowed into the process chamber for a period of greater than or equal toabout 60 seconds. In one or more embodiments, the period of exposure tothe metal precursor is about 100 seconds, about 200 seconds, about 300seconds, about 400 seconds or about 500 seconds.

The temperature of the substrate during exposure to the metal precursorcan be controlled, for example, by setting the temperature of thesubstrate support or susceptor. This temperature is also referred to asthe deposition temperature. In one or more embodiments, the substrate ismaintained at a temperature below the decomposition temperature of themetal precursor. In one or more embodiments, the substrate is maintainedat a temperature below the decomposition temperature of the alkyl halidecatalyst. In one or more embodiments, the substrate is maintained at atemperature between the decomposition temperature of the alkyl halidecatalyst and the decomposition temperature of the metal precursor.

In one or more embodiments, the substrate is maintained at a temperatureless than or equal to about 400° C., or less than or equal to about 350°C., or less than or equal to about 300° C., or less than or equal toabout 250° C., or less than or equal to about 200° C. In one or moreembodiments, the substrate is maintained at a temperature greater thanor equal to about 150° C., or greater than or equal to about 200° C., orgreater than or equal to about 250° C., or greater than or equal toabout 300° C., or greater than or equal to about 350° C. In one or moreembodiments, the substrate is maintained at a temperature of about 225°C. or about 280° C.

In one or more embodiments, the deposition process is performed as athermal process without the use of plasma reactants. Stated differently,in one or more embodiments, the method is performed without plasma.

In one or more embodiments, at operation 860, it is determined whetherthe metal film has achieved a predetermined thickness. If thepredetermined thickness has not been achieved, the method 800 returns to850 to continue exposing the substrate to the metal precursor until thepredetermined thickness is reached. Once the predetermined thickness hasbeen reached, the method 800 can either end or proceed to 870 foroptional further processing. In one or more embodiments, the metal filmmay be deposited to form a total layer thickness of about 10 Å to about10,000 Å, or in one or more embodiments, about 20 Å to about 1000 Å, orin one or more embodiments, about 50 Å to about 200 Å.

One or more embodiments of the disclosure selectively deposit a metalfilm on a metal surface over a first dielectric surface. These methodsare similar to method 800 as described above. The substrate providedcomprises a dielectric surface and a metal surface. In one or moreembodiments, a substrate as illustrated in FIG. 9 is processed toselectively form bottom up gap fill on the metal surface at the bottom916 of the feature 910.

The metal of the metal film and the metal of the substrate surface maybe the same metal or may be different metals. The dielectric surface maybe formed from any suitable dielectric material. In one or moreembodiments, the dielectric material comprises nitrogen or oxygen atoms.Without being bound by theory, it is believed that these materials reactwith the alkyl halide catalyst and prevent the halogen from adsorbingonto the substrate surface so as to catalyze the reaction with the metalprecursor. Accordingly, little, if any, metal film is formed on thedielectric surface.

In one or more embodiments, the deposition temperature is below thedecomposition temperature of the halogen catalyst, e.g. alkyl halidecatalyst. Again, without intending to be bound by theory, it is believedthat if the alkyl halide catalyst decomposes, the halogen will beavailable for reaction with the metal precursor on all surfaces(regardless of composition), leading to metal film deposition on allsubstrate surfaces, including the dielectric surface. In one or moreembodiments, the deposition temperature is at or above the decompositiontemperature of the halogen catalyst, e.g. alkyl halide catalyst.

One or more embodiments of this disclosure advantageously providemethods for controlling the deposition of a metal film. In one or moreembodiments, the rate of deposition is controlled. In one or moreembodiments, the location of deposition is controlled.

The methods of various embodiments use methods of atomic layerdeposition (ALD) or chemical vapor deposition (CVD) to form the metalfilms. The above disclosure describes an exemplary ALD process withrespect to FIG. 7 and an exemplary CVD process with respect to FIG. 8.

As stated previously, the generalized deposition processes shown inFIGS. 7 and 8 are performed as thermal processes without the use ofplasma reactants. The use and effect of plasmas and other additionalreactants is discussed further below.

One or more embodiments of the disclosure advantageously provide methodsof depositing metal films within substrate features or other structures.Exemplary features or structures include, but are not limited to,trenches and vias.

One or more embodiments of the disclosure advantageously providedeposition control methods for reducing film deposition outside of atarget feature and near the feature opening. Without being bound bytheory, it is believed that reducing deposition in these areas allowsfaster gap fill within the target feature and reduces clogging near thefeature opening and formation of voids or seams within the feature.

Referring to FIGS. 7 and 8, without limiting the scope of the abovedisclosure, both the ALD and CVD processes described above utilize analkyl halide catalyst and a metal precursor to deposit a metal film.Without being bound by theory, it is believed that the alkyl halidecatalyst functions as a catalyst in the deposition of the metal film.Accordingly, as particularly evidenced by the CVD process, a singleexposure of the substrate surface to an alkyl halide catalyst can beused to deposit a thickness of more than 10 nm of metal film.

One or more embodiments of the disclosure advantageously providedeposition control methods for reducing the activity of the catalyst inpredetermined areas of the substrate surface. In one or moreembodiments, the activity of catalyst is reduced. In one or moreembodiments, the activity of the catalyst is eliminated.

Referring to FIGS. 10A-10D, an exemplary substrate 400 is shown duringprocessing according to one or more embodiments of this disclosure. Thesubstrate 1000 illustrated in FIGS. 10A-10D is simplified forexplanation. As mentioned above, and shown in FIG. 9, in one or moreembodiments, the substrates of this disclosure contain features orstructures not depicted in FIGS. 10A-10D.

In FIG. 10A, the substrate 1000 contains a substrate surface 1010. InFIG. 4B, the substrate surface 1010 is exposed to a halogen catalyst,e.g. alkyl halide catalyst, to form an activated surface 1020. Asdescribed above, the halogen catalyst, e.g. alkyl halide catalyst, 1040adsorbs to the substrate surface 1010 to form an activated substratesurface 1020.

In FIG. 10C, a predetermined area of the activated surface 1020 isexposed to a deactivation treatment to form a deactivated surface 1030.The halogen catalyst, e.g. alkyl halide catalyst, 1040 shown in FIGS.10B and 10C is shown as circular or ovoid, however no specific molecularshape is intended to be conveyed. Similarly, the difference between thecircular shapes shown in FIGS. 10B and 10C and the ovoid shapes shown inFIG. 10C is meant only to convey the activity and/or relativeconcentration of alkyl halide catalyst on the substrate surfaces.

In FIG. 10D, the substrate 1000 is exposed to a metal precursor to forma metal film 1050. As shown in FIG. 10D, the thickness T₁ of the metalfilm 1050 on the activated surface 1020 is greater than the thickness T₂of the metal film 1050 on the deactivated surface 1030.

In one or more embodiments, the deactivation treatment reduces theconcentration of the halogen catalyst, e.g. alkyl halide catalyst, onthe activated surface 1020. In one or more embodiments, the deactivationtreatment reduces the catalytic activity of the halogen catalyst, e.g.alkyl halide catalyst, on the activated surface 1020.

In one or more embodiments, the method described above with respect toFIGS. 10A-10D is modified to include the deactivation treatment beforeexposure to the halogen catalyst, e.g. alkyl halide catalyst. In thisregard, the deactivation treatment may be understood to “superactivate”a predetermined area of the substrate surface 1010 before exposure tothe halogen catalyst, e.g. alkyl halide catalyst. Upon exposure to thehalogen catalyst, e.g. alkyl halide catalyst, the “superactivated”surface forms a higher concentration or activity of catalyst than asurface not exposed to the deactivation treatment. The difference inconcentration and/or activity between the surfaces may be used tocontrol deposition. In one or more embodiments, the surfaces may befurther deactivated as described above with respect to FIGS. 10C-10D.

The thickness T₁ is greater than the thickness T₂. Accordingly, one ormore embodiments of the disclosure advantageously provide depositioncontrol methods for controlling the amount of deposition inpredetermined areas of the substrate surface.

In one or more embodiments, the ratio of T₁:T₂ is greater than or equalto about 1:1, greater than or equal to about 2:1, greater than or equalto about 3:1, greater than or equal to about 4:1, greater than or equalto about 5:1, or greater than or equal to about 10:1. In one or moreembodiments, little to no deposition of metal occurs on the deactivatedsurface 1030. Stated differently, in one or more embodiments, thicknessT₂ is about 0. Stated differently, the amount of metal film 1050deposited on the deactivated surface 1030 is essentially none. As usedin this regard, “essentially none” means that the metal film on thedeactivated surface covers less than 5%, less than 2%, less than 1% orless than 0.5% of the deactivated surface.

The thicknesses of the metal film 1050 deposited on the activatedsurface 1020 and the deactivated surface 1030 is directly proportionalto the rates of deposition on the activated surface 1020 and thedeactivated surface 1030. Accordingly, one or more embodiments of thedisclosure advantageously provide deposition control methods forcontrolling the rate of deposition in predetermined areas of thesubstrate surface.

In one or more embodiments, the entire substrate surface is exposed tothe deactivation treatment. One or more embodiments of the disclosuremay be used to control the amount of deposition on the entire substrate.One or more embodiments of the disclosure may be used to control therate of deposition on the entire substrate.

In one or more embodiments, not shown, the substrate 1000 comprises oneor more features. In one or more embodiments, the deactivated surface1030 is the surface outside of the one or more feature. In one or moreembodiments, the deactivated surface 1030 is the surface near the top ofthe sidewall of the one or more feature.

Without being bound by theory, it is believed that the surface nearsubstrate features and the top surfaces of the sidewalls of thosefeatures are more highly activated (exhibits greater deposition) due tomultiple exposed faces within close proximity. The greater deposition onthese surfaces increases the likelihood that the feature will closebefore a sufficient amount of film is formed inside of the feature. Whenfeatures close a seam or void is often formed. Accordingly, in one ormore embodiments, the deactivated surface 1030 is the surface near thetop of the one or more feature. Further, in one or more embodiments, thedeactivated surface 1030 is the surface near the substrate feature. Inone or more embodiments, the metal film deposited within the feature hasreduced seams or voids. In one or more embodiments, the metal filmdeposited within the feature has substantially no seam or voids. As usedin this regard, the term “substantially no seam” means that any gapformed in the film between the sidewalls is less than about 1% of thecross-sectional area of the sidewall.

In one or more embodiments, the predetermined areas of the substrate areexposed to hydrogen gas without the use of plasma.

In one or more embodiments, a hydrogen gas pulse is introduced into theALD deposition cycle described above. Stated differently, a substratemay be exposed to a pulse sequence of alkyl halide catalyst, purge,hydrogen gas, purge, metal precursor, purge. In one or more embodiments,the substrate is exposed to an additional pulse of hydrogen gas followedby a purge after exposure to the metal precursor. In one or moreembodiments, the substrate is exposed to an additional pulse of hydrogengas followed by a purge after exposure to the alkyl halide catalyst. Inone or more embodiments, the purge phase between each exposure to themetal precursor and/or the alkyl halide catalyst is performed in some,but not all cycles.

In one or more embodiments a hydrogen gas exposure is introduced intothe CVD deposition cycle described above. Stated differently, asubstrate may be soaked with the alkyl halide catalyst, exposed tohydrogen gas and exposed to the metal precursor. In one or moreembodiments, the substrate is exposed to the hydrogen gas beforeexposure to the metal precursor. In one or more embodiments, thehydrogen gas and the metal precursor are flowed simultaneously.

In one or more embodiments, the predetermined areas of the substrate areexposed to a plasma comprising one or more of hydrogen (H₂), ammonia(NH₃) or argon (Ar). In one or more embodiments, the plasma used todeactivate the surface is a low powered plasma. In One or moreembodiments, the plasma has a power in a range of about 50 W to about500 W, in a range of about 50 W to about 300 W, in a range of about 50 Wto about 200 W, or in a range of about 50 W to about 100 W.

In one or more embodiments, the plasma exposure time is less than orequal to about 30 seconds, less than or equal to about 20 seconds, lessthan or equal to about 15 seconds, less than or equal to about 10seconds, less than or equal to about 5 seconds, or less than or equal toabout 2 seconds.

In one or more embodiments, the plasma is a conductively coupled plasma(CCP). In one or more embodiments, the plasma is an inductively coupledplasma (ICP). In one or more embodiments, the plasma is a direct plasmagenerated within the processing environment. In one or more embodiments,the plasma is a remote plasma generated outside of the processingenvironment.

In one or more embodiments, a plasma pulse is introduced into the ALDdeposition cycle described above. In one or more embodiments, the plasmapulse replaces the hydrogen gas pulse described above with respect tothe ALD deposition cycle.

In one or more embodiments, a plasma pulse is introduced into the CVDdeposition cycle described above. In one or more embodiments, the plasmapulse replaces the hydrogen gas exposure described above with respect tothe CVD deposition cycle.

The use of the terms “a” and “an” and “the” and similar referents in thecontext of describing the materials and methods discussed herein(especially in the context of the following claims) are to be construedto cover both the singular and the plural, unless otherwise indicatedherein or clearly contradicted by context. Recitation of ranges ofvalues herein are merely intended to serve as a shorthand method ofreferring individually to each separate value falling within the range,unless otherwise indicated herein, and each separate value isincorporated into the specification as if it were individually recitedherein. All methods described herein can be performed in any suitableorder unless otherwise indicated herein or otherwise clearlycontradicted by context. The use of any and all examples, or exemplarylanguage (e.g., “such as”) provided herein, is intended merely to betterilluminate the materials and methods and does not pose a limitation onthe scope unless otherwise claimed. No language in the specificationshould be construed as indicating any non-claimed element as essentialto the practice of the disclosed materials and methods.

Reference throughout this specification to “one embodiments,” “certainembodiments,” “one or more embodiments” or “an embodiment” means that aparticular feature, structure, material, or characteristic described inconnection with the embodiments is included in at least one embodimentsof the disclosure. Thus, the appearances of the phrases such as “in oneor more embodiments,” “in certain embodiments,” “in one embodiments” or“in an embodiment” in various places throughout this specification arenot necessarily referring to the same embodiments of the disclosure. Inone or more embodiments, the particular features, structures, materials,or characteristics are combined in any suitable manner.

Although the disclosure herein has been described with reference toparticular embodiments, it is to be understood that these embodimentsare merely illustrative of the principles and applications of thepresent disclosure. It will be apparent to those skilled in the art thatvarious modifications and variations can be made to the method andapparatus of the present disclosure without departing from the spiritand scope of the disclosure. Thus, it is intended that the presentdisclosure include modifications and variations that are within thescope of the appended claims and their equivalents.

What is claimed is:
 1. A method of depositing a film, the methodcomprising: forming a film on a substrate surface by exposing thesubstrate surface to a precursor of general formula (I): M-L₁(L₂)_(y),wherein M is a metal, L₁ is an aromatic ligand, L₂ is an aliphaticligand, and y is a number in the range of from 2 to 8, wherein L₂comprises 1,5-hexdiene, 1,4-hexadiene, and less than 5% of1,3-hexadiene.
 2. The method of claim 1, wherein the metal M is selectedfrom one or more of molybdenum (Mo), ruthenium (Ru), cobalt (Co), copper(Cu), platinum (Pt), nickel (Ni), or tungsten (W).
 3. The method ofclaim 1, further comprising, prior to forming the film, forming anactivated substrate surface by exposing the substrate surface to ahalogen catalyst.
 4. The method of claim 1, wherein the substratesurface has at least one feature formed therein, the at least onefeature having a sidewall and a bottom.
 5. The method of claim 1,wherein the aromatic ligand, L₁, comprises a pi electron system selectedfrom η², η⁴, η⁶, and η⁸.
 6. The method of claim 5, wherein the aromaticligand, L₁, comprises 1-methyl-4-isopropylbenzene.
 7. The method ofclaim 1, wherein the aliphatic ligand, L₂, further comprises anasymmetric cyclic diene.
 8. The method of claim 7, wherein theasymmetric cyclic diene comprises one or more of3-(2-propenyl)-cyclohexene, 1-(2-propenyl)-cyclohexene,1,3-propadiene-cyclohexane, and 1,2-divinylcyclohexane.
 9. The method ofclaim 7, wherein y is a number in a range of from 2 to 6, and whereinthe ratio of 1,5-hexadiene to the sum the 1,4-hexadiene, 1,3-hexadiene,and the asymmetric cyclic diene is in a range of from about 50:50 toabout 60:40.
 10. The method of claim 4, wherein a surface of adielectric material forms the sidewall and a surface of a metallicmaterial forms the bottom.
 11. The method of claim 10, furthercomprising depositing a metal nitride liner in the at least one feature.12. The method of claim 3, further comprising depositing a seed layer onthe substrate surface before exposing the substrate surface to thehalogen catalyst.
 13. The method of claim 1, wherein exposing thesubstrate surface to the halogen catalyst comprises soaking a substratein an alkyl halide catalyst.
 14. The method of claim 13, wherein thealkyl halide catalyst comprises iodoethane or diiodomethane.
 15. Amethod of depositing a film, the method comprising: exposing a substratesurface to a halogen catalyst to form an activated substrate surface;and exposing the activated substrate surface to a precursor of generalformula (I): M-L₁(L₂)_(y), wherein M is a metal, L₁ is an aromaticligand, L₂ is an aliphatic ligand, and y is a number in the range offrom 2 to 8 to form a metal film on the substrate surface, wherein theL₂ comprises 1,5-hexdiene, 1,4-hexadiene, and less than 5% of1,3-hexadiene.
 16. The method of claim 15, wherein the aromatic ligand,L₁, comprises a pi electron system selected from η², η⁴, η⁶, and η⁸. 17.The method of claim 15, wherein the substrate surface has at least onefeature formed therein, the at least one feature having a sidewall and abottom.
 18. The method of claim 17, further comprising depositing ametal nitride liner in the at least one feature.
 19. The method of claim15, wherein exposing the substrate surface to the halogen catalystcomprises soaking a substrate in an alkyl halide catalyst.
 20. Anon-transitory computer readable medium including instructions, that,when executed by a controller of a processing chamber, causes theprocessing chamber to perform operations of: exposing a substratesurface to a halogen catalyst to form an activated substrate surface;and flowing a precursor into a processing volume of the processingchamber having the substrate, the precursor having general formula (I):M-L₁(L₂)_(y), wherein M is a metal, L₁ is an aromatic ligand, L₂ is analiphatic ligand, and y is a number in the range of from 2 to 8, whereinthe L₂ comprises 1,5-hexdiene, 1,4-hexadiene, and less than 5% of1,3-hexadiene.